Nervous Control of Movements in the Foregut of Schistocerca gregaria Forsk.

Abstract

OBSERVATIONS on the nervous control of movement in the foregut of insects were first made by Marchal1, who showed that in Dytiscus marginalis L. swallowing movements were abolished by the removal of the frontal ganglion. Yeager2, in Periplaneta fuliginosa Serv., and Chauvin3, in P. americana L., showed that the movements of the crop were independent of the intact nervous system. Further, Chauvin found that in P. americana L. the movements of the gizzard were dependent upon the presence of an intact nervous system; but in Locusta migratoria L. movements occurred in the whole isolated gut and were unaffected by agents such as acetylcholine and eserine. In general, movements of the gut are thought to be influenced by the ganglia of the visceral nervous system; but, with the exception of the work of Marchal, this does not appear to have been actually demonstrated in any insect. Arising from work still in progress upon the movements of the gut of Schistocerca gregaria Forsk., evidence presented in this communication was obtained of the visceral nervous control of some of the movements of the gut.